For example, in a blow molding machine disclosed in patent document 1, many mold components are used. Since the mold components are made according to the sizes and shapes of containers to be blow molded, when the sizes and shapes of the container are changed according to a manufacturing lot, the mold components must be replaced.
When the same container is mass produced, the frequency of replacement of the mold components is low. However, recently, since the kinds of containers to be molded have increased and multi-kind small-quantity lots have increased, when the replacement frequency of the mold components increases, there is raised the need to reduce the burden of the mold component replacing operation.